DESCRIPTION: (Principal Investigator's Abstract) Molecularly imprinted polymers are highly crosslinked organic matrixes that can be readily synthesized to have binding affinity and selectivity for a wide range of molecules, macromolecules and even cells. Proposed is the application of a novel strategy to improve the selectivities of molecularly imprinted polymers (MIPs). Selective post-modification of the imprinted polymers leads to a material with more homogeneity and selectivity among its binding sites. The principle is to selectively inactivate low affinity sites so that the resulting MIP has higher overall binding affinity and selectivity. This strategy differs from previous attempts to improve the properties of MIPs which have all relied on optimization of the imprinting process. The benefits to the health field will be drugs and pharmaceuticals of higher purity and inexpensive sensors that can be tailored to particular analytes.